Britain's surveillance agency GCHQ, with aid from the National Security Agency, intercepted and stored the webcam images of millions of internet users not suspected of wrongdoing, secret documents reveal.

GCHQ files dating between 2008 and 2010 explicitly state that a surveillance program codenamed Optic Nerve collected still images of Yahoo webcam chats in bulk and saved them to agency databases, regardless of whether individual users were an intelligence target or not.